1. Field of the Invention
The present invention relates to an image forming system capable of performing printing in which an image is formed on a sheet, and the sheet is output and performing a plurality of post-processings for the printed sheet as desired and a post-processing method.
2. Description of the Related Art
In image forming apparatuses in which an image is printed on a sheet, such as copying machines, printers, facsimile, and multi-function machines, desired post-processing can be performed for a sheet on which an image is printed. Generally, post-processing is performed by a post-processing apparatus that is connected to the rear stage of an image forming apparatus. As post-processing apparatuses, for example, there are a side stitching apparatus, a saddle stitching apparatus, a folding apparatus, a punching apparatus, a binding apparatus, a stapling apparatus, and a cut-processing apparatus.
In an image forming system configured by at least an image forming apparatus and a post-processing apparatus as above, printing and post-processing are performed, for example, based on a job set by the image forming apparatus side. In the setting of a job, the size, the weight, and the paper type of a sheet and the content of post-processing, and the like can be set. In addition, in a case where a plurality of post-processing units are included, a plurality of post-processings can be set.
Meanwhile there is a restriction on the size of a sheet that can be processed by each post-processing unit. Thus, when the post-processing is set, it is determined whether a sheet fed from a feed tray has a sheet size for which post-processing can be performed before printing, printing is permitted only in a case where the sheet has a sheet size for which the post-processing can be performed, and printing is not permitted in a case where the sheet has a sheet size for which post-processing cannot be performed (for example, see Japanese Unexamined Patent Application Publication No. 2007-86568).
In addition, in Japanese Unexamined Patent Application Publication No. 2007-86568, it has also been proposed that, in a case where the length of one side of a sheet housed in the feed tray for which post-processing is performed is not permitted for the post-processing, the other side is checked, and, in a case where the other side is permitted for the post-processing, an error message is not displayed, whereby the error is automatically resolved, and the operability is improved.
In addition, there are post-processing apparatuses each including a slitter which cuts a sheet. In an image forming system including such a post-processing apparatus, in a case where another post-processing is performed using a post-processing apparatus connected to the downstream side of the slitter, a sheet is cut by the slitter, and accordingly, there is a problem in that it cannot be correctly determined whether the post-processing can be performed based on information of the sheet size set in the feed tray. When an incorrect determination is made, there is concern that a sheet for which the post-processing cannot be performed is fed so as to cause the occurrence of a jam in a post-processing unit, or a job is not correctly performed.
The present invention have an object to providing an image forming system and a post-processing method capable of correctly determining whether to perform post-processing even in a case where post-processing in which the size of a sheet changes due to cutting of the sheet or the like is included.